The ultrastructural localization of the fibrous proteins of the nerve ending will be investigated using an indirect immunoperoxidase electron microscopic methodology. The protein subunits corresponding to desmin, axonal 100A filaments and tubulin will be used as immunogens to prepare antisera and as affinity chromatography reagents to purify monospecific antibodies from the antisera. The specificity of the antibodies will be proven by a newly devised technique in which the proteins are separated by two-dimensional electrophoresis and stained with the antibody by an indirect immunoperoxidase method. The relationship between the cytoskeleton and the synaptic plasma membrane will also be explored by the further development of in vitro techniques for the assembly of tubulin into membranes rather than microtubules. Tubulin purified from in vitro assembled membranes and microtubules will be compared and the factors which determine whether tubulin assembles into membranes or microtubules will be defined.